Manufacture of steel ingots



' UNITED STATES PATENT OFFIC NIVEN MOCONNELL, OF MUNHALL, PENNSYLVANIA.

MANUFACTURE oF STEEL moors.

SPECIFICATION forming part of Letters Patent No. 587,105, dated July 27, 1897. Application filed May 6, 1896. Renewed. May 21, 1897. Serial No. 637,626- (No model.)

To all whom it may concern:

Be it known that I, NIVEN MoOoNNELL, of Munhall, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in the Manufacture of Steel Ingots, of which the following is a full, clear, and exact description.

The object of my invention is to improve the manufacture of steel ingots for the purpose of preventing the tendency to rise in the mold which mild steel has when tapped from the open-hearth furnace in which it is refined,

and poured from the ladle into the ingotmolds;

I have discovered that if a very small percentage of aluminium, either pure or as an alloy, is added in the mold into which the steel is being poured the steel will settle down in the mold and lie quietly without such ebullition as occurs when poured without addition of aluminium, or when the aluminium is added in small proportion either in the furnace or in the ladle. By this addition I do not seek to effect the increase of the fluidity of the steel nor the lowering of its melting point, but the purpose of its addition is to quiet the metal and to prevent its ebullition, as above stated,without inj uriously affecting the ingot. This effect is not produced when the alumini-v um is added before pouring the steel.

The beneficial effect of my invention is se-/ cured by the use of a very minute quantityf of metallic aluminium. In practice I prefer: to use about two ounces of aluminium to the ton (two thousand two hundred and forty pounds) of steel. My practice is to put the aluminium preferably as a solid lump filled with steel, say when it has been filled about one third. The very small proportion of aluminium requisite for my process (about fifty-five ten-thousandths of one per cent.) as compared with what has been heretofore used inother processes, as well as the vast difference in result which follows my method of adding the aluminium in the mold, as distinguished from adding it before it is introduced into the mold, clearly distinguish my invention.

I do not add the aluminium in proportions as high as one-tenth of one per cent. to the steel. It will be found that if aluminium is added in such high proportions it will produce a deleterious efiect and will cause the formation of large cavities near the top of the ingot. I do not, therefore, regard the use ofaluminium in such large proportions as being part of my invention.

Idisclaim the addition of aluminium to steel while the steel is in the ladle or in the furnace as being outside the scope of my invention and as not suited to the obtaining of the result which I secure by my method; but

What I claim is An improvement in the manufacture of /steel ingots, which consists in tapping steel from the furnace in which it has been refined, pouring it into an ingot-mold, and adding to it in the mold a small percentage of aluminium; substantially as described.

In testimony whereof I have hereunto set my hand.

NIVEN MOCONNELL.

Witnesses:

THoMAs W. BAKEWELL,

intolthe mold after the mold has be enpartly G. I. HOLDSHIP. 

